Ustilaginoidea virens
Encyclopedia
Ustilaginoidea virens, perfect sexual stage Villosiclava
virens, is a plant pathogen which causes the disease False Smut of rice
which reduces both grain yield and grain quality. The disease occurs in more than 40 countries, especially in the rice producing countries of Asia. but also in the U.S. As the common name suggests, it is not a true smut (fungus)
, but an ascomycete. False smut does not replace all or part of the kernel with a mass of black spores, rather sori form erupting through the palea and lemma forming a ball of mycelia, the outermost layers are spore-producing. Infected rice kernels are always destroyed by the disease.
Of particular concern are the production of alkaloids in the grain as with the Claviceps spp. causing ergot
.
Little is known of the exact life cycle of the pathogen. There is debate among plant pathologists at what time infection of the plant occurs. There are reports of early, systemic infections of seedlings and other reports of later infection at boot or flowering.
Villosiclava
Villosiclava is a genus of fungus in the Clavicipitaceae family. This is a monotypic genus, containing the single species Villosiclava virens. Villosiclava virens, also known by the name of its anamorph Ustilaginoidea virens, is a rice pathogen which causes the false smut disease....
virens, is a plant pathogen which causes the disease False Smut of rice
Rice
Rice is the seed of the monocot plants Oryza sativa or Oryza glaberrima . As a cereal grain, it is the most important staple food for a large part of the world's human population, especially in East Asia, Southeast Asia, South Asia, the Middle East, and the West Indies...
which reduces both grain yield and grain quality. The disease occurs in more than 40 countries, especially in the rice producing countries of Asia. but also in the U.S. As the common name suggests, it is not a true smut (fungus)
Smut (fungus)
The smuts are multicellular fungi, that are characterized by their large numbers of teliospores. The smuts get their name from a Germanic word for dirt because of their dark, thick-walled and dust-like teliospores. They are mostly Ustilaginomycetes and can cause plant disease...
, but an ascomycete. False smut does not replace all or part of the kernel with a mass of black spores, rather sori form erupting through the palea and lemma forming a ball of mycelia, the outermost layers are spore-producing. Infected rice kernels are always destroyed by the disease.
Of particular concern are the production of alkaloids in the grain as with the Claviceps spp. causing ergot
Ergot
Ergot or ergot fungi refers to a group of fungi of the genus Claviceps. The most prominent member of this group is Claviceps purpurea. This fungus grows on rye and related plants, and produces alkaloids that can cause ergotism in humans and other mammals who consume grains contaminated with its...
.
Little is known of the exact life cycle of the pathogen. There is debate among plant pathologists at what time infection of the plant occurs. There are reports of early, systemic infections of seedlings and other reports of later infection at boot or flowering.